JPH08339676A - Magnetic disk unit - Google Patents

Abstract

PURPOSE: To obtain a magnetic disk unit in which the adhesion of a magnetic head to a magnetic disk is released by applying an impact force to an airtight enclosure by utilizing a springy force. CONSTITUTION: A magnetic disk 1 is mounted on an enclosure 3 via a spindle motor 2. The enclosure 3 comprises an airtight part, and impact-force application mechanisms 11, 12, 13, 14 which utilize a springy force are installed at the outside of the airtight enclosure 3. When an impact force is applied to the enclosure 3, the impact force is transmitted to a magnetic head and a magnetic disk medium (a substrate), and a very small displacement or a very small vibration is generated. By the displacement or the like, the adhesion of the magnetic head to the magnetic disk 1 is released.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact and low power consumption magnetic disk device, and more particularly to a magnetic disk device having a mechanism for releasing adhesion between a magnetic head and a magnetic disk.

2. Description of the Related Art The size of a computer is a desktop,
Laptop, notebook size, notebook size and miniaturization is progressing. In other words, the miniaturization of magnetic disk devices in the market, coupled with the progress of high recording density technology, is the so-called 3.5 inch type to 2.5 inch type, 1.8 inch type, which uses the diameter of the magnetic disk medium as a guide. Furthermore, 1.
We have advanced to the 3-inch type. A magnetic disk device built in or detachably incorporated in a portable computer having a notebook size or less is mainly a 2.5-inch type or less. Next, reduction in power consumption of the small magnetic disk device will be described. With the miniaturization of magnetic disk devices, card-type removable magnetic disk devices have become popular. Regarding such card type magnetic disk devices and other electronic devices, as standardization including mechanical attachment / detachment and electrical connection (interface), the Japan Electronic Industry Development Association (JEIDA) and the US PCM
CIA (Personal Computer Memory Card International)
ICs for personal computers that the Association has been promoting in cooperation
There are standard specifications for memory cards. These standard specifications are
Initially, it was not intended for a magnetic disk device, but it has been expanded to include a magnetic disk device and other interface devices as the magnetic disk device is downsized. In the standard specifications of these IC memory cards for personal computers, the operating environment can be set so that they can be used with other cards in the system or in the system. Also, if the operating environment provided by the card does not satisfy the operating environment required by the system, the system can refuse to use the card. This operating environment includes parameters relating to power supply condition information. This parameter includes standard operating power supply voltage, minimum operating power supply voltage, maximum operating power supply voltage, continuous power supply current, maximum value of average current for 1 second,
The maximum value of the average current for 10 milliseconds, the supply current required in the power down mode, and the like are included. in this way,
Low power consumption is particularly required for small magnetic disk devices such as card type magnetic disk devices, which are expected to be used mainly for portable information equipment with a built-in battery. As a typical conventional technology for reducing power consumption, US Pat. No. 4,
933,785 (Corresponding Japanese application, Special Publication 3-5031
01), the operation mode is (1) a sleep mode in which other circuit functions are stopped while leaving a minimum interface connection function with a host necessary for restarting,
(2) Spindle motor is rotating, some servo functions are operating, and data recording / reproducing circuit is stopped. (3) Write / read / seek normal operation mode, etc. There is a way. In each operation mode, the power consumption of the circuits corresponding to unnecessary functions is suppressed. This method has the effect of reducing the power consumption in an average usage state. However, it is also important to reduce the power consumption of individual circuit components including the spindle motor as much as these. For this reason, in many spindle motors for rotating a magnetic disk medium for a small-sized magnetic disk device, the maximum current is limited, and the initial starting torque tends to be small due to the downsizing and thinning of the motor itself. The same applies to the torque of the rotary voice coil motor for driving the actuator of the magnetic head. Next, the adhesion phenomenon between the magnetic head and the magnetic disk medium will be described. In the contact start / stop type magnetic disk device, the magnetic disk medium starts rotating in a contact stopped state in which the magnetic head slider is pressed against the magnetic disk surface, and the magnetic disk medium at the position of the slider reaches a predetermined peripheral speed. Then, until the slider is sufficiently floated from the magnetic disk surface by the dynamic pressure,
The magnetic head slider slides while making contact with the surface of the magnetic disk medium. After that, the slider is sufficiently floated from the surface of the magnetic disk by the dynamic pressure to function (magnetic head flying type magnetic disk device). To improve the wear resistance of the magnetic head slider and the surface of the magnetic disk, a surface lubricant that covers the surface of the magnetic disk is used. The surface lubricant is also used in a contact type magnetic disk device in which the magnetic head or the magnetic head slider functions while maintaining contact with the magnetic medium. The magnetic head contact type magnetic disk device can achieve higher recording density than the magnetic head floating type magnetic disk device. However, when the magnetic head slider and the magnetic disk medium, which have extremely high flatness, are in a state where the surface lubricant is interposed and the adhesion is stopped for a long time, an adhesion phenomenon often occurs. The sticking phenomenon causes a startup failure of the magnetic disk device. Therefore, various devices have been devised to prevent the sticking phenomenon from occurring and to release the sticking state. As a method of not causing tackiness fundamentally, Japanese Patent Laid-Open No. 13477/1993 by the applicant of the present application
0 and later patent publications by different applicants
03101 (corresponding U.S. Pat. No. 4,933,785) is a lamp loading technique. This holds the magnetic head suspension on a tapered holding member attached above the magnetic disk medium,
The magnetic head slider is held in non-contact with the surface of the magnetic disk medium. In this method, it is necessary to secure a space between magnetic disk media for holding and to add a holding member. Further, as a method for making stickiness less likely to occur, there is a method disclosed in Japanese Patent Publication No. 57-8530 by another applicant. In a magnetic disk device of the magnetic head contact type, this is to form a contact start / stop zone (a region where the magnetic head slider comes into contact with the magnetic medium when the rotation of the medium is stopped) on the surface of the magnetic disk medium, and to form such a zone. Is a method (zone texture technique) of roughening the surface of the medium to reduce the flatness. The effect of this method has a trade-off relationship with the improvement of wear resistance. It is difficult to completely prevent sticking and the manufacturing cost increases. There are also various methods of devising the characteristics of the surface lubricant, but it is difficult to completely prevent sticking only with this method. JP-A-6-203514 by another applicant discloses
There is disclosed a method in which a projection is provided on the magnetic head slider to reduce the contact area with the magnetic disk medium and reduce stiction (static friction force). In this method, it is necessary to consider in order to avoid physical damage caused by sliding between the slider and the magnetic disk medium by a protrusion provided on the magnetic head slider. As a method for releasing the adhesion, there is a method using a starting force of a magnetic disk spindle motor or a rotary voice coil motor for driving a magnetic head actuator. Japanese Patent Publication No. 57-60707 by another applicant and U.S. Pat. No. 4,542,429 by the applicant of the present application move a magnetic head slider in a radial direction of a magnetic disk medium immediately before starting rotation of a magnetic disk to release adhesion. A method is disclosed.
Japanese Patent Publication No. 61-61191 by another applicant discloses a method of releasing adhesion by vibrating a magnetic head slider by a voice coil motor for driving a magnetic head actuator at the time of starting rotation of a magnetic disk. Japanese Patent Application No. 61-211230 by another applicant (corresponding U.S. Pat. No. 4,
897,743) discloses a method of pressing the magnetic head actuator against an elastic stopper by an actuator motor before the rotation of the magnetic disk is started, and finely moving the magnetic head slider in the radial direction of the magnetic disk medium to release the adhesion. . However, there is a known technique for releasing these adhesions in a small and low power consumption magnetic disk device in which the starting torque of a magnetic disk spindle motor and the torque of a rotary voice coil motor for driving a magnetic head actuator are small. No technique has been shown to provide the release force. As another method for releasing the adhesion, there is JP-A-6-208771 (corresponding US Pat. No. 5,313,352) by another applicant. Here, a method is disclosed in which a plurality of vibrating elements are provided in the magnetic head slider portion to vibrate the magnetic head slider in a predetermined vibration mode to release the adhesion. This method complicates the magnetic head slider portion and increases the manufacturing cost.

SUMMARY OF THE INVENTION A magnetic disk drive which has a small starting torque of a spindle motor and a starting torque of a rotary voice coil motor (VCM) for driving a magnetic head actuator, and which is suitable for a small-sized and low power consumption magnetic disk device. It is to realize a magnetic disk device having a mechanism for releasing the adhesion between a head (slider) and a magnetic disk medium.

This can be achieved by providing a mechanism for applying an impact force to a housing of a magnetic disk device having a hard magnetic disk medium such as a glass substrate.

When an impact force is applied to the housing, the impact force is transmitted to the magnetic head and the magnetic disk medium, and causes minute displacement or minute vibration, respectively. Adhesion is released by this displacement or the like.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A simple structure and operation of a magnetic disk device will be described with reference to FIG. Figure 1 shows a contact start-stop system (hereinafter C) equipped with a manual impact force application mechanism.
FIG. 3 is a perspective view of a magnetic disk device of SS system). The magnetic disk 1 is mounted on the housing 3 via a spindle motor 2. For the magnetic disk 1, hard glass, aluminum or other non-magnetic material is used. The magnetic head slider 4 is attached to the housing 3 via a pivot bearing 5, a carriage 6 and a gimbal 7. During operation, the magnetic disk 1 is rotated at a high speed by the spindle motor 2, and the magnetic head slider 4 is a fluid (air in the housing) generated by the rotation of the magnetic disk 1.
It is emerging using the dynamic pressure of. The magnetic head uses the magnetic circuit of the flying magnetic head slider 4 and the magnetic disk 1 to record and reproduce information on and from the magnetic disk 1. When not operating, the magnetic head slider 4 is
It is pressed against the CSS zone 8 outside the data area on the surface of the magnetic disk 1 by the gimbal 7 and comes into close contact with it to stop. By stopping this adhesion, the magnetic disk 1
Adhesion between the magnetic head slider 4 and the magnetic head slider 4 often occurs. Here, if the adhesive force between the magnetic disk 1 and the magnetic head slider 4 is larger than the starting torque of the spindle motor 2 and the VCM torque of the carriage 6, the apparatus will not start and a failure will occur. The principle of tack release in the present invention will be described with reference to FIG. FIG. 2 is a schematic diagram showing how the impact force is transmitted. When a shock is applied to the housing 3, the applied shock force has components as shown by arrows 9-a and 9-b, and the magnetic disk 1 and the magnetic head slider 4 respectively.
Transmitted to. Between the magnetic disk 1 and the magnetic head slider 4, a force component 9-a in the direction perpendicular to the magnetic disk 1,
The horizontal force component 9-b or the resultant force acts. The vertical component 9-a vibrates the magnetic head slider 4,
The magnetic disk 1 is repeatedly pressed to remove the adhesive force. Further, since the horizontal component 9-b also exerts a force in the shearing direction with respect to the adhesive force, the adhesion between the magnetic disk 1 and the magnetic head slider 4 can be released. Next, one embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the impact force applying unit 11, the spring 12, the core rod 13, and the collar 14 are provided outside the closed casing of the casing 3.
The impact force applying mechanism consisting of Impact force application unit 11
Has a spherical contact portion with the housing 3 to concentrate the impact force. The spring 12 is arranged between the collar 14 and the housing 3, and is normally in a fully extended state. Core rod 13
Is provided with a step, and when it is pulled, it collides with the housing 3,
It works as a stopper. In addition, the housing 3 is
The brim 14 and the core rod 13 serve as a guide at two points. If the core rod 13 is manually pulled and released here, the spring 12
The elasticity of allows the impact force application unit 11 to give an impact to the housing 3. Here, since the impact force applying mechanism is arranged outside the closed casing of the apparatus, dust generation by the impact force applying unit 11 does not pose a problem. The result of actually releasing the adhesion using such a mechanism is shown in FIG. FIG. 3 is a relationship diagram between the spring constant of the spring 12 used in the impact force applying mechanism and the releasable adhesive force. The magnetic disk device used for the measurement is
This is a 1.8-inch magnetic disk device (thickness 10.5 mm) having two magnetic disk media and four magnetic heads. The impact force application position and direction were set to the position shown in FIG. 1 where there is a space in the 1.8-inch magnetic disk device. The medium (substrate) of the magnetic disk 1 is made of glass,
The housing 3 is made of aluminum, and the impact force applying section 11 is made of iron. The vertical axis shows the releasable adhesive force (gf) and the impact force (G) on the device at that time, and the horizontal axis shows the spring constant (N / m).
Is shown. Further, assuming that the shock resistance of the device is 150 G and the starting torque of the spindle motor 2 is 15 gf, a constant is added to FIG. When the adhesive force is 15 gf or less, the adhesion can be released by the starting torque of the spindle motor 2, and the magnetic disk device is started. However, when the adhesive force exceeds 15 gf, the adhesive cannot be released by the starting torque of the spindle motor 2 and the spindle motor 2 does not rotate. Here, if a shock of 75 G or more and 150 G or less is applied to the housing 3, the adhesion corresponding to the relationship of FIG. 3 can be released without damaging the device and without damaging the magnetic disk medium. The operation of the device becomes possible. Since the applied impact force depends on the movable distance (displacement of the spring),
In the magnetic disk device for measurement, the magnetic disk device was made as large as possible, and the position of the step of the core rod 13 was set to 7 mm. Further, the spring constant is set to 5.25 N / m in consideration of variations.
If the variation in applied impact force is ± 10 G, an impact of at least about 130 G can be applied, and correspondingly, the adhesion can be released against the adhesive force of 26 gf. However, the relationship of FIG. 3 is limited because it depends on a number of factors such as the direction of impact, the time of impact, the type of surface lubricant, the surface condition of the magnetic disk medium, the structure of the magnetic disk device, and many other factors. It doesn't mean that. Also,
The shock resistance of the magnetic disk device and the starting torque of the spindle motor are not limited to these. Theoretically, shock resistance can be achieved up to the breaking point of the magnetic disk 1 or the magnetic head slider 4. Magnetic disk medium (substrate)
However, the material is not limited to glass, but may be ceramic, titanium, or carbon alone, or a composite material or alloy containing these as the main components, which is strong in impact resistance capable of withstanding repeated hits of the magnetic head slider 4. The position and direction of impact are also
It is not limited to those shown above. Further, if the spring constant is made small, it can be applied to a magnetic disk medium made of an ordinary aluminum base material. 4, FIG. 5, FIG. 6, FIG. 7, and FIG.
Now, another embodiment equipped with a manual impact force applying mechanism will be described. FIG. 4 is a perspective view of a magnetic disk device equipped with an impact force applying mechanism utilizing the elasticity of a material. The numbers of the same members as those in FIG. 3 are omitted. As shown in FIG.
An elastic member 16-a is attached to the outside of the with a screw 15. By releasing the elastic member 16-b from the state of being manually pulled, the elasticity can be utilized to apply an impact to the housing 3. However, the shape of the elastic member 16 and the fixing method thereof are not limited to the above. In this method, it is possible to apply a shock to the housing 3 with a simple mechanism. Figure 5
The part of the impact force applying mechanism using a spring is shown in FIG. The impact force application unit 17 is rotatable around a fulcrum 18. Normally, the impact force application unit 17 is in contact with the housing 3 by the spring 19. When releasing the adhesion, the impact force applying portion 17 is released while the portion indicated by the arrow 20 is manually pushed. The impact force application unit 17 includes a spring 19
By this, the original state is restored, and a shock can be applied to the housing 3. However, the shape of the impact force application portion 17, the position of the fulcrum 18, the shape of the spring 19, the way of applying the spring force, and the like are not limited to the above. In this method, since the rotation angle of the impact force applying section 17 can be made constant, the impact force to be applied can be made constant, and there is no fear of damaging the magnetic disk device due to excessive impact. Further, there is an effect that the impact force can be easily adjusted by the rotation angle of the impact force application unit 17, the material, the material of the housing 3, the spring force of the spring 19, and the like. FIG. 6 is a diagram showing a portion of an impact force applying mechanism using a magnet. The impact force application unit 21 has a metal piece 22 embedded therein and is rotatable by a fulcrum 23. On the other hand, a magnet 24 is embedded in the housing 3. When attempting to release the adhesion, the impact force application section 21 is pushed in the direction of arrow 25. The metal piece 22 of the impact force application unit 21 can be attracted to the magnet 24 of the housing 3 to give an impact to the housing 3. However, the shape of the impact force applying section 21,
The position of the fulcrum 23, the relationship between the magnet 24 and the metal piece 22, and the like are not limited to the above. This mechanism is suitable for applying a relatively small impact. FIG. 7 is a diagram showing a portion of an impact force applying mechanism using an iron ball. FIG. 8 is a relationship diagram between the mass of the iron ball 26 used in the impact force applying mechanism and the releasable adhesive force. As shown in FIG. 7, the iron ball 2 is attached to a part of the housing 3.
Make a space 27 larger than 6 and put the iron ball 26 in it. When the housing 3 tilts or shakes to some extent, the iron ball 26 rolls and hits the housing 3, so that an impact can be given. The result of actually releasing the adhesion is shown in FIG.
As the magnetic disk device, the same device as in FIG. 3 was used. The vertical axis shows the releasable adhesive force (gf) and the impact force (G) on the device at that time, and the horizontal axis shows the mass (g) of the iron ball 26. The applied acceleration is 30 m / s. According to this, if a movable distance of 20 mm can be secured, 0.4
By using an iron ball of g, it is possible to apply an impact of 140 G and release the adhesive strength of 28 gf. However,
If the material and size of the sphere, the shape and size of the space 27, and other conditions are changed, the result is not limited to that shown in FIG. In this method, when the magnetic disk device is adhered, the adhesion can be released by shaking the magnetic disk device, and at the same time, a shock is given at any time by carrying the magnetic disk device, carrying the computer main body, or the like, which also prevents the adhesion.
Further, operations such as attachment / detachment of the spindle motor, VCM, and device are used for the above-mentioned mechanism, and the iron ball 26 is operated by the magnet force during operation.
It is even better to add a mechanism that can fix the. The method of applying an impact is not limited to the above. Also,
Electric shock or vibration may be applied. Impact or vibration may be applied in conjunction with the insertion / removal of the magnetic disk device. It may be linked with the insertion / removal between the packing case and the magnetic disk device (may be linked with the packing itself). Further, the CSS zone 8 may be separately provided outside the data area of the magnetic disk medium. Further, the mechanism for applying the impact force may be linked with the insertion / extraction of the magnetic disk device, installation, unpacking, unsealing, or storage in a storage case.

By providing a simple member, it is possible to install an impact force applying mechanism for giving a minute displacement to a magnetic head, a magnetic disk and other mechanical parts of a magnetic disk device. The minute displacement provided by this mechanism can release the adhesion between the magnetic head and the magnetic disk medium. As a result, the magnetic disk device can be operated smoothly. Further, since a glass substrate or other magnetic disk medium having high rigidity is used, even if an impact force is applied, no dent mark of the magnetic head remains on the surface of the magnetic disk medium. Furthermore, dust generation by the release mechanism has an effect that does not pose a problem.

[Brief description of drawings]

FIG. 1 is a perspective view of a contact start / stop type magnetic disk device equipped with a manual impact force applying mechanism.

FIG. 2 is a schematic diagram showing how an impact force is transmitted.

FIG. 3 is a relationship diagram of a spring constant of a spring used in an impact force applying mechanism and a releasable adhesive force.

FIG. 4 is a perspective view of an apparatus equipped with an impact force applying mechanism utilizing elasticity of a material.

FIG. 5 is a partial view of an impact force applying mechanism using a spring.

FIG. 6 is a partial view of an impact force applying mechanism using a magnet.

FIG. 7 is a partial view of an impact force applying mechanism using an iron ball.

FIG. 8 shows the mass of the iron ball used in the impact force applying mechanism,
It is a related figure of the adhesive force which can be released.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disk 3 ... Housing 4 ... Magnetic head slider 11 ... Impact force application part 12 ... Spring 16 ... Elastic member 17 ... Impact force application part 19 ... Spring 21 ... Impact force application part 22 ... Metal piece 24 ... Magnet 26 ... Iron ball 27 ... Space

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Ito 2880, Kozu, Odawara-shi, Kanagawa Stock Company Hitachi Storage Systems Division (72) Inventor Hiroshi Nishida 2880, Kozu, Odawara, Kanagawa Hitachi Storage Co., Ltd. System Division (72) Inventor Toshiyuki Ohno 2880, Kozu, Odawara, Kanagawa Stock Company, Hitachi Storage Systems Division (72) Inventor, Kojiro Hayashi, 2880, Kozu, Odawara, Kanagawa Storage Systems Division, Hitachi, Ltd.

Claims (3)

[Claims] 1. A magnetic disk medium, a spindle for rotatably supporting the disk medium, a magnetic head for writing or reading information to or from the disk medium, a slider for mounting the head, and the magnetic disk. An actuator that moves the head to an arbitrary position on the magnetic disk medium and maintains the position; and an electronic circuit that controls at least the processing of the information, the movement or maintenance of the actuator, and the rotation of the spindle. A magnetic disk device having a hermetically-sealed housing for storing these, wherein the hermetically-sealed housing is provided with a mechanism for applying an impact force. 2. The magnetic disk device according to claim 1, wherein the mechanism for applying the impact force is provided in a hermetically sealed housing portion different from a portion for storing the magnetic disk medium. . 3. The magnetic disk device according to claim 1, wherein the magnetic disk medium is glass, ceramic, titanium,
Alternatively, a magnetic disk device whose main material is carbon.